u-boot/board/keymile/km83xx/km83xx_i2c.c

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/*
* (C) Copyright 2011
* Holger Brunck, Keymile GmbH Hannover, holger.brunck@keymile.com
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <i2c.h>
#include <asm/io.h>
#include <linux/ctype.h>
#include "../common/common.h"
static void i2c_write_start_seq(void)
{
struct fsl_i2c *dev;
dev = (struct fsl_i2c *) (CONFIG_SYS_IMMR + CONFIG_SYS_I2C_OFFSET);
udelay(DELAY_ABORT_SEQ);
out_8(&dev->cr, (I2C_CR_MEN | I2C_CR_MSTA));
udelay(DELAY_ABORT_SEQ);
out_8(&dev->cr, (I2C_CR_MEN));
}
int i2c_make_abort(void)
{
struct fsl_i2c *dev;
dev = (struct fsl_i2c *) (CONFIG_SYS_IMMR + CONFIG_SYS_I2C_OFFSET);
uchar last;
int nbr_read = 0;
int i = 0;
int ret = 0;
/* wait after each operation to finsh with a delay */
out_8(&dev->cr, (I2C_CR_MSTA));
udelay(DELAY_ABORT_SEQ);
out_8(&dev->cr, (I2C_CR_MEN | I2C_CR_MSTA));
udelay(DELAY_ABORT_SEQ);
in_8(&dev->dr);
udelay(DELAY_ABORT_SEQ);
last = in_8(&dev->dr);
nbr_read++;
/*
* do read until the last bit is 1, but stop if the full eeprom is
* read.
*/
while (((last & 0x01) != 0x01) &&
(nbr_read < CONFIG_SYS_IVM_EEPROM_MAX_LEN)) {
udelay(DELAY_ABORT_SEQ);
last = in_8(&dev->dr);
nbr_read++;
}
if ((last & 0x01) != 0x01)
ret = -2;
if ((last != 0xff) || (nbr_read > 1))
printf("[INFO] i2c abort after %d bytes (0x%02x)\n",
nbr_read, last);
udelay(DELAY_ABORT_SEQ);
out_8(&dev->cr, (I2C_CR_MEN));
udelay(DELAY_ABORT_SEQ);
/* clear status reg */
out_8(&dev->sr, 0);
for (i = 0; i < 5; i++)
i2c_write_start_seq();
if (ret != 0)
printf("[ERROR] i2c abort failed after %d bytes (0x%02x)\n",
nbr_read, last);
return ret;
}